1. Field of the Invention
The present invention relates to a substrate developing method, a substrate processing method, and a developing solution supply nozzle.
2. Description of the Related Art
In a photolithography process in fabrication processes of a semiconductor device, resist coating treatment in which a resist film is formed by applying a resist solution on a film to be etched that is formed on a surface of, for example, a wafer, exposure processing in which the resist film on the wafer is exposed in a predetermined pattern, development treatment in which the resist film is developed by supplying a developing solution to the exposed wafer, and etching treatment in which the film to be etched is etched, using the resist film in the predetermined pattern as a mask, and so on are performed in sequence.
In the photolithography process, an anti-reflective film is sometimes formed as a base film of the resist film prior to the resist coating treatment in order to, for example, prevent the resist film from being excessively exposed by light which is reflected on the film to be etched after transmitting through the resist film during the exposure processing.
When, for example, the base film is thus formed between the film to be etched and the resist film, it is necessary to separately etch the base film on an upper layer of the film to be etched before the film to be etched is etched. The etching treatment of this base film has been generally conducted in such a manner that an etching gas is plasmatized in a chamber housing a wafer to cause a chemical reaction of a surface of the base film with plasma particles (Japanese Patent Application Laid-open No. Hei 8-97191).
However, due to the use of high-energy plasma particles in the etching treatment of the base film, the resist film is greatly damaged, and for example, as shown in FIG. 14, a surface of a resist film R on an upper layer is etched off to sometimes cause great inclination of a side face of the resist film R which should be in a rectangular shape.
With such inclination of the side face of the resist film R, in the etching treatment of the film to be etched, the film to be etched is etched more than necessary to become smaller than a predetermined size, so that a pattern with a desired line width and dimension is not formed on the wafer. Especially in recent years when high density and microfabrication of semiconductor devices are progressing, realizing a photolithography process with high dimensional precision has become an important issue.
Further, in the conventional etching treatment of the base film, a large amount of an upper surface of the resist film R is also sometimes etched off in a vertical direction. This reduces the total film thickness of the resist film R and the base film, which sometimes disables the resist film R from fully functioning as a mask for the film to be etched.